This invention relates to teaching or instructional devices for use in classrooms and, more particularly, to teaching devices for use in teaching the operation of hand-held calculators.
Teachers have experienced difficulties in the explanation of the operation of hand-held calculators because such calculators are of such a small size that students seated in a classroom are unable to see the keys of the calculator, and the resulting calculator display, as the keys are depressed by an instructor standing in the front of the classroom.
One prior art device has sought to cure part of this problem by providing an enlarged numerical display operably connected to a hand-held calculator. This device is illustrated in the McCarty U.S. Pat. No. De. 252,301 issued July 10, 1979 and is produced by Educational Calculator Devices of Laguna Beach, Calif. The device, however, does not permit the students in the classroom to see which keys are depressed by the instructor.